From The Blog

Jasper’s Itch

In all of creation puppies rank near the top of the list in the category of cutest things ever!  Labrador Retriever puppies are especially...

In all of creation puppies rank near the top of the list in the category of cutest things ever!  Labrador Retriever puppies are especially endearing.  Their plump little bodies, soft fur, innocent expression, clumsy antics, and limitless desire for human affection make them absolutely irresistible!  Anyone who has ever tried to walk away from a litter of seven-week-old Lab puppies without taking one home can attest to this.  If you happen to bring children with you for the meet and greet the level of difficulty increases dramatically! It becomes almost impossible to go home empty handed!

So it was for Jasper’s family when he came to live in their household.  An 8 week old, energetic little yellow Lab full of spunk and wiggle and kisses for anyone willing to pick him up and hold him close.  I met him a week later when the Scott family brought him to my office for his first puppy visit.  He pranced through the door sporting a brand new John Deere leash and collar ensemble, supremely confident that everyone inside must have come specifically to play with him!  He made his way around the room introducing himself to staff and clients alike, seeming to delight in the opportunity to collect as many pats and hugs and ooh’s and aahh’s as possible.

When it was his turn to come back to the exam room his whole body wagged with anticipation as I reached down to pick him up.  He clambered up my chest and onto my shoulder with his front feet, and I dodged his repeated attempts to lick me on the face and head.  I hugged on him for a few minutes, enjoying the unbridled enthusiasm and the pleasant smell of puppy breath!  Needing to stay on schedule as much as possible, I peeled him off my shoulder and handed him to my assistant.  She would attempt to hold him somewhat still while I examined him from head to toe, feeling, listening, smelling him until I was convinced I had examined him thoroughly.  His family looked on with proud smiles and anxious anticipation of a good report from the doctor!

Jasper passed his physical exam with flying colors.  He seemed to be the picture of health.  I updated his immunizations.  We treated him for internal and external parasites.  We discussed nutrition, heartworm prevention, potty training and all the normal stuff we try to talk to new puppy parents about on their first visit.  Jasper was as rambunctious as ever and by this point he was bored with this vet visit stuff.  The Scott’s gathered up their paperwork and headed up to the front desk to check out.  The whole process was complicated slightly by the impatient puppy tugging on the end of the leash and hopping around as Ms. Scott attempted to retrieve her wallet from her purse and locate her debit card!  Eventually they got checked out and on their way.  We watched them all get into the car and drive away with smiles on their faces.  It never ceases to amaze me how even with all the sleepless nights, potty accidents, chewed up belongings and other headaches associated with owning a new puppy, the joy and love that they bring into a home with their infectious good nature and never ending supply of welcome home greetings somehow makes it all worthwhile.

I saw Jasper back for more immunizations a few weeks later and I was pleased to see that everything was going exceptionally well.  He looked great on physical exam.  His growth was appropriate.  He was fully assimilated into the family now.  Everyone was sleeping through the night.  The potty training was coming along faster than expected, and everyone – human and canine – seemed to be doing great.

However, when he was around 6 months old the situation began to change drastically.  At first the Scott’s really didn’t think much of it.  They figured it was probably normal – maybe just a phase of development.  Each week, though, it seemed to get worse.  Jasper was scratching himself constantly!  He could hardly take two steps now without stopping to scratch or bite.  His once thick, full hair coat became thin and sparse.  Bald spots started showing up on his chest and legs.   He shook his head frequently and pawed at his ears with his back feet.  Eventually the bald spots developed scabs and scaly lesions that looked angry and painful.  The Scott’s were at their wits end.  They had done everything they knew to do.  They treated him for fleas.  They dipped him with some dip they bought at the pet store that said it cured mange.  The added oil to his food and even tried giving him benadryl on the advice of a neighbor whose dog was prone to spells of itching.  Nothing seemed to help.  They called and scheduled and appointment to bring him in.

When I saw him in the exam it was hard for me to believe he was the same dog I had seen a few months earlier.   He had grown considerably and lost some of that “puppy” look, but mostly I was struck by the appearance of his skin and hair.  His once luxurious blonde coat looked moth-eaten.  His skin was bright pink and he felt greasy to the touch.  There were scabby sores randomly scattered all over his body.  His ears were red and swollen and filled with stinky yellow goo.  When I would touch him his skin would crawl and he would scratch with a hind foot at an imaginary spot in the air. He looked pitiful!  I thought to myself, he looks like a smelly version of the Velveteen Rabbit after all his fuzz was worn off !

Despite the appearance of his skin he seemed to feel fine otherwise.  His body never stopped wagging.  As I ran my fingers over his inflamed skin he licked me on the forehead and whacked me with his tail.  He was eager to flop over on his side for a belly rub so I could inspect the condition of his underside.  Despite his skin condition, he was still a happy-go-lucky Labrador Retriever with limitless energy and an insatiable appetite for attention.  This time, though, the Scott family watched with furrowed brows and anxious anticipation for what I was going to say about Jasper’s skin.  We didn’t know it at the time, but this day would mark the beginning of a long and difficult saga for Jasper and the Scott family.

Itchy dogs and cats are one of the most common presenting complaints we encounter in private practice.  Unfortunately, it’s a relatively non-specific sign. There are probably a dozen reasons or more why pets get itchy skin.  External parasites like fleas, ticks and mites are a common cause of itchy skin, as are fungal skin infections like ringworm and chemical irritants that might be present in plant resins or certain shampoos.  Biting flies and mosquitoes can make dogs itchy, as well as less common autoimmune diseases like pemphigus or lupus.  However, one of the most common reasons for dogs and cats to present with itchy skin in the southeast is allergies.

Allergies are a type of hypersensitivity reaction to small substances in our environment that are not usually harmful.  In individuals that are prone to allergies contact with these substances activates the immune system and triggers an inflammatory cascade.  Any substance that elicits an allergic response is called an allergen.  For humans the word allergy conjures up images of people with runny eyes, sneezing, snuffy nose and congestion.  However, the allergic response in canines and felines differs from that of humans to some degree.  Whereas most allergic humans manifest their allergies in the respiratory tract, dogs and cats primarily manifest their allergies through their skin.  Thus, instead of getting runny eyes and a stuffy nose, (although this can happen) dogs and cats tend to get red, itchy skin.   The ears and feet seem to be especially sensitive to allergic skin disease.  Recurrent ear infections and/or feet chewing may be the only signs of allergies we see in some patients.

When I am discussing allergies with my clients in the exam room I find it helpful to break the major sources of allergens down into three categories – flea, food and environmental.  Most allergic patients have contributions from at least two of the three categories.  Some patients may have contributions from all three categories.  This occurs because patients that have allergies are genetically predisposed to allergies and they are never allergic to just one thing.  Normally, the clinical signs that we see in an allergic patient are the result of contributions from a handful of different allergens.  In our quest for a solution to the problem our goal is not to systematically address every single allergen, but to somehow identify the main contributing allergens.  If we can address the top few allergens we normally see a stepwise reduction in the severity of the skin problem.  Some patients may appear to be “cured” at this point whereas others may just be improved.

Usually, the first category we discuss is food allergens.  The most common offending ingredients for dogs are beef, wheat gluten and dairy, but there are other ingredients that may be problematic for certain patients.  Patients suffering from food allergy are often some of the itchiest.  They may also have intermittent GI upset as part of the history as well.  Patients with food allergies will often become symptomatic at an earlier age than those suffering from other types of allergies.  The signs and symptoms are usually less seasonal.  Food allergy patients don’t respond to medication to manage the itching as well as patients with allergies to other things.  In many cases patients with food allergies have recurrent ear infections and/or an itchy, swollen anus.  Veterinary dermatologists have a saying – ears and rears in combination is food allergy until proven otherwise!  There are no reliable tests for specific food allergens so our approach to diagnosing food allergy is to select a hypoallergenic food and feed only approved ingredients for 8-10 weeks.  Normally at this point we are trying to get secondary bacterial and yeast infections under control as well.  The hope is that once the secondary infections are cleared up and enough time as elapsed on the hypoallergenic diet for the allergic response to quiet down, that the signs will not return.

The second main category of allergen we discuss is flea saliva.  Any pet that is allergic to anything will be allergic to flea saliva.  It is one of the most reactive allergens our pets encounter.  Many times I have pet owners tell me in the exam room that fleas can’t be making their pet itch because they only see an occasional flea.  In response to that statement I usually remind them that people that are allergic to bees don’t have to be stung by the whole hive to have a reaction.  Recurrent exposure to even small amounts of flea saliva can be enough to keep an allergic pet itchy all summer long.  Dogs with flea allergy tend to have a very characteristic pattern of hair loss and skin lesions.  The worst areas tend to be around the base of the tail and down the backs of the thighs.  The scabs and hair loss will often be noticeable further up the middle of their back as well.  If I see this pattern on an itchy patient I’m immediately considering flea saliva as a possible contributing factor even if I don’t see any live fleas on the pet.  One other factoid to keep in mind with flea allergy is that flea allergic dogs will be itchy for up to two weeks after the last flea is gone if the itching is not addressed with medication.   This causes many pet owners to question if fleas are really an issue because they expect the itching to stop within a few days of applying flea medication.  When, in fact, they may just need to keep applying monthly flea products and be patient.

I mention these two categories first because in formulating a treatment plan for an allergic pet, which I will touch on shortly, these categories are the easiest to address.  There are good topical and oral medications for fleas as well as good limited ingredient diets available over the counter for dogs now.  However, if addressing these two major categories doesn’t solve our problem we have to consider the third main category – environmental allergens.

Environmental allergens are small particles present in nature that are either breathed in or in contact with an animals skin.   This includes every type of weed, grass and tree pollen, every variety of mold spore, cat dander, dust mites, mold mites and storage mites.  Anything that a human could be allergic to in the spring, a dog or cat can be allergic to as well. This variety of allergy is called atopy.  Atopy is a collective medical term for reaction to any of these environmental allergens.  You will often see the word used in the context of an atopic patient or atopic dermatitis.  That’s just dermatology lingo for an animal that has significant environmental allergens or a skin condition due to environmental allergens.  Differentiating atopy from food or flea allergy is necessary because, through skin testing or serologic allergy testing, it is possible to determine which of these environmental allergens a patient reacts to.  If specific allergens can be identified then extracts of those allergens can be prepared for immunologic allergy therapy.  How immunotherapy works is beyond the scope of this blog.  But, the basic idea is that allergens are injected into a patient to hyposensitize (make them less reactive) them to those allergens.  Seventy percent of patients with atopy undergoing immunotherapy are significantly improved after a few months of therapy.

As I mentioned earlier, there are normally other secondary lesions present in a allergic patient that have to be addressed before we can expect significant improvement.  Most patients with allergic dermatitis regardless of the underlying cause have significant skin infections – either bacteria and/or yeast.  Getting these secondary issues under control requires managing the itch AND eliminating the infection.  Usually a combination of oral and topical therapy is necessary for a minimum of three weeks.  If the under lying allergen can be identified and eliminated then there is a good chance the skin condition will not return.  However, if it can’t then this will likely be a recurrent problem!

One of the main concepts I try to convey to my clients with allergic pets is the fact that we cannot cure allergies.  We manage allergies.  Managing allergies requires diligence and commitment and a genuine desire to help a pet improve.  I also tell my clients that problems associated with allergies vary greatly in severity.  There is an entire spectrum of allergic patients from those that only need good flea products, to those that require regular immunotherapy.  Each pet is different and we need to let our response rise to the level of the problem.  If your allergic pet just needs a round of corticosteroids and antibiotics twice a year to keep them comfortable then we probably shouldn’t consider food trials, allergy testing or other daily medication.  However, if your allergic pet gets itchy and uncomfortable as soon the meds start to run out, then we need to consider taking additional measures to address the underlying allergies.

What do I mean by addressing the underlying allergies?  Typically there is a progression that I go through with an allergic patient in trying to determine exactly what our treatment plan should include.  I usually start by trying to eliminate the easiest two of the three major categories of allergens that we discussed previously.  That means our first order of business is religious flea control!  You remember when we were talking about flea allergies I stressed that any pet that is allergic to anything will be allergic to flea saliva.  No matter what lengths we go to to manage allergies, if the allergic patient has fleas it will be a waste of time.   My favorite products for controlling fleas in the allergic patient are Nexguard, Bravecto, Comfortis and Activyl.  All of these products work well when used regularly.  There are other products that work well like for some households like Advantage, Seresto collars and Frontline.  Sometimes it just takes a few months of regular administration to determine which product is going to suit your particular situation best.  It is possible to treat fleas in the environment as well.  That can dramatically reduce the overall flea population.  If you choose to do an area treatment be certain to choose a product with an insect growth regulator. Insecticides that only kill adult fleas don’t really impact the population very much when applied to the environment.  Remember, most allergic patients have multiple allergens contributing to their condition, however, just eliminating fleas is often enough to move a patient from the poorly controlled category to the well controlled category.

The second order of business for a severely allergic pet is to eliminate any contribution from food allergy – even if the condition is seasonal.  Remember, our signs – itching, inflammation, etc – are the culmination of all the allergens present in the environment at any one time.  If food allergens are a smoldering, relatively small source of allergen exposure, they may not be causing severe signs in the winter when environmental allergens and fleas are scarce.  However, when spring arrives the contribution of environmental allergens may cause a patient to cross the “allergic threshold” and begin to become symptomatic.  If we can eliminate the contribution from dietary allergens we can reduce the allergic “burden” on the pet and we may see a reduction in the severity of the condition.  Eliminating dietary allergens requires feeding either a limited ingredient diet or a prescription, hydrolyzed diet like Purina HA or Hill’s Z/D.   The most common reactive ingredients for dogs are beef, wheat gluten and dairy.  Other ingredients can cause reaction in certain pets.  There is no way to know for sure.  The least reactive protein sources are duck, venison, rabbit and fish – usually in that order.  Good carbohydrate sources are potato, sweet potato and rice.  Hydrolyzed diets seem a little hocus-pocus at first glance, but it is technology borrowed from the infant formula industry.  The protein sources are cleaved with enzymes in the production process so theoretically the molecules are too small to trigger the allergic response.  My clients sometimes find that confusing because the ingredient label doesn’t look very hypoallergenic, but it works.  It is critically important when conducting a diet trial that all other sources of dietary allergens are eliminated.  This means using only approved treats and giving only approved snacks from the table!  It can take up to 10 weeks to really evaluate the effects of a low allergen diet for some patients.   I’ll just mention that with some allergic pets we end up discovering that they can’t eat dry dog food.  It may be due to storage mite allergies.  We don’t usually know for sure, but in these patients the best alternative is a canned or home cooked diet.  Cooking for your pet can be a good, lower cost alternative for managing the diet.  There are great cookbooks available with recipes for different types of food.  Many of the less common meats can be ordered on-line or located at specialty grocers.  Most of my clients who cook for their pets fix a big batch once or twice a week then refrigerate individual meals in Ziploc bags until it is fed.

My other recommendation for all allergic pets doesn’t specifically target food or fleas. However, weekly medicated baths are an an effective way to help with atopy and recurrent skin infections.    Allergists used to believe that atopy was strictly an issue of inhaled allergens.  More recent evidence points to the possibility that many of these environmental allergens may be surface active.  That is, direct contact with skin may also result in triggering the allergic response.  These allergens build up over time in the hair.  Washing regularly with a medicated shampoo removes the allergens and it also helps keep the yeast and bacterial populations on the skin in check.  Using a hydrocortisone leave on conditioner after baths is an additional step that is often very effective at controlling the itch.  There are other steps we can take to help manage allergies such as using antihistamines daily. Antihistamines don’t work very well for dog allergies if we wait until they are already itchy.  That is partly because of the pharmacology of the drug and partly because histamines seem to be a minor player in dog allergies.  Supplementing the diet with omega fatty acids can be beneficial, as well as installing HEPA filters in the HVAC within the home.

If these steps are taken and a pet is still poorly controlled, then it is time to talk to your vet about allergy testing and immunotherapy or regular administration of cyclosporine orally.

As you can image, determining how to manage a patient with allergic dermatitis can take several visits and involve considerable cost.  It is often very frustrating for a pet owner when signs keep returning regardless of what we do.  In Jasper’s case, his owner’s were very persistent and determined.  We did skin scrapes to check for mites and we didn’t find any.  We treated empirically for a type of contagious mite that is commonly found in dogs, but is hard to find on skin scrapings.  We tried different prescription diets.  When he was taking prednisone and antibiotics he was moderately well controlled, but lifelong prednisone administration is fraught with serious risk and complication.  Almost every allergic pet will require short courses of prednisone or similar medication to control their itching, but it is not a good long-term maintenance strategy.

When our efforts didn’t result in satisfactory results for Jasper, I convinced Jasper’s owners to take him to see a veterinary dermatologist.  They weren’t happy with the plan that came out of that visit.  They ended up back in my office even more frustrated and no closer to a solution.  We decided to refer Jasper to the University of Georgia College of Veterinary Medicine.  There they developed a plan that managed his skin fairly well.  For the first time in his adult life Jasper had a full coat of hair again and smooth, white skin.  But, it came at a considerable cost.  He was taking cyclosporine, an immunosuppressive drug used commonly in human medicine for recipients of organ transplants to prevent their body from rejecting the transplanted tissue.  He was receiving immunotherapy for a long list of allergens that he had reacted to in his allergy testing.  He was on a strict hypoallergenic diet.  And, he still had to take a low dose of methylprednisone every other day to control his itching in the summer time.  As often happens with cases like his that are extremely labor intensive and incurable, fatigue sets in after a while – emotional, financial and physical.  The family gradually stopped coming back for their scheduled recheck visits, and eventually we lost contact with them.

I still think about Jasper from time to time. I hope his skin is fairly comfortable. I get occasional second-hand updates on him from neighbors or friends if they happen to be in the office.  It makes me sad that as a profession we don’t have better tools to manage his disease.

Cases like his stretch the limits of the human-animal bond.  Jasper is fortunate to have a family with the determination and the financial means to continue dealing with his skin.  Many animals are not so fortunate and either end up being humanely euthanized because of their terrible skin problems or just living a miserable, itchy existence.  Fortunately, dogs with allergies as severe as Jasper’s are relatively rare.  Nonetheless, if you are considering getting a puppy, it pays to do your homework.  Allergies are largely hereditary.  Ask the breeder if either of the puppies parents have recurrent skin problems or have to be fed a special diet.  Being selective and diligent in your search for your next four-legged family member, no matter how cute and cuddly they might be, can help insure a long, happy itch-free relationship!

 

Allergies are a menace to humans and pets alike!  If you think your pet may suffer from allergies, talk to you veterinarian.  He or she is you best source for good information and guidance.

 

 

 


No comments yet.

Leave a Reply

You must be logged in to post a comment.